Channel culture devices, which provide multiple plant growth channels of indefinite length but of shallow depth and narrow individual width, have enormous potential value for increasing the world's food supply. They provide maximum plant production for a given supply of fertile soil, water, fertilizer, and insecticide, some or all of which are scarce and at an extreme premium in many parts of the world. The growth channels have a limited cross-sectional area that can be made just sufficient for the full root development of any specified plant, so that optimum availability of nutrients and water to the plants is obtained. Further, the isolation of the channels prevents the leaching and escape of the available supply of nutrients and water into the underlying soil. Isolation also simplifies the problems of cultivation, and of the control of pests, disease, and weeds.
The difficulty that must be overcome before channel culture devices can be widely used is the cost, and in many needful parts of the world the scarcity, of materials for their construction. Various design proposals have been made, of which some are disclosed and claimed in my copending U.S. patent application, Ser. No. 512,518, filed Oct. 7, 1974, for "Channel Culture Device." The ideal structure would be easy to set up quickly without skilled labor, would require only locally-available materials or light-weight materials easy to transport, and would be as cheap as possible. At the same time, the device must have structural stability so that it will not collapse under the weight of soil and water it contains.
It is the general object of this invention to provide an improved channel culture device, which employs nothing but light sheet material for its construction, requires no fasteners or anchors, and yet affords adequate structural stability and integrity for its purpose. It is a further and more specific object to improve the structural resistance of such a device to the large lateral forces that can be imposed by the outward pressure of wet soil, without resorting to braces, ASTENERS, OR HEAVY STRUCTURAL MEMBERS, BUT USING ONLY LIGHT SHEET MATERIALS SUCH AS CORRUGATED CARDBOARD, PLASTIC, OR SHEET METAL.